1. Field of the Invention
This invention relates generally to static VAR generators and more particularly to static VAR generators employing controlled inductance means switched in combination with capacitance means into an AC network to regulate power factor and terminal voltage.
2. Description of the Prior Art
The basic function of a static VAR generator is to supply controlled reactive power for an electrical network to reduce terminal voltage variation and to improve load power factor. Inherent in all static VAR generator designs utilizing anti-parallel switching thyristors is a delay in response resulting from the requirement that a sampling of the systems reactive demand must be made plus computations determining the reactive compensation prior to any corrective action. Additionally, after the computations are complete the output current for the VAR generator can be adjusted only once in each half cycle. Consequently, after the first sampling and computation time elapses, if the reactive demand should change suddenly, the VAR generator cannot further adjust its output current until the next half cycle. It would be desirable for a VAR generator design to have the capability to allow further corrective action to be taken in response to any reactive demand change that may occur after the first sampling and computation time interval for each half cycle.